Data from: Adaptation to an invasive host is driving the loss of a native ecotype

Locally adapted populations are often used as model systems for the early stages of ecological speciation, but most of these young divergent populations will never become complete species. The maintenance of local adaptation relies on the strength of natural selection overwhelming the homogenizing effects of gene flow; however, this balance may be readily upset in changing environments. Here I show that soapberry bugs (Jadera haematoloma) have lost adaptations to their native host plant (Cardiospermum corindum) and are regionally specializing on an invasive host (Koelreuteria elegans), collapsing a classic and well-documented example of local adaptation. All populations that were adapted to the native host-including those still found on that host today-are now better adapted to the invasive host in multiple phenotypes. Weak differentiation remains in two traits, suggesting that homogenization across the region is incomplete. This study highlights the potential for adaptation to invasive species to disrupt native communities by swamping adaptation to native conditions through maladaptive gene flow.本地适应种群（locally adapted populations）常被用作生态物种形成早期阶段的模式系统，但这类年轻的分化种群绝大多数永远无法演化成为完整物种。本地适应的维持依赖于自然选择的强度足以抵消基因流的均质化效应；然而在环境变化的背景下，这一平衡极易被打破。本研究显示，皂荚长蝽（soapberry bugs, Jadera haematoloma）已丧失对本土宿主植物倒地铃（Cardiospermum corindum）的适应性，并在区域尺度上特化利用入侵宿主台湾栾树（Koelreuteria elegans），这一现象瓦解了一个经典且被充分记录的本地适应案例。所有原本适应本土宿主的种群——包括现今仍在该宿主上发现的种群——如今在多个表型上均更适应入侵宿主。仍有两个性状存在微弱分化，这表明区域内的均质化过程尚未完全完成。本研究揭示，对入侵物种的适应可通过适应不良的基因流淹没本土适应进程，进而对本土群落造成破坏。